JPH0425335B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Object of the Invention (1) Industrial Application Field The present invention relates to a method for manufacturing a reinforcing cylindrical fiber molded body used for fiber reinforcing a metal member or the like.

(2) Conventional technology Conventionally, this type of fiber molded article is produced by sealing the openings at both ends of an air-permeable cylindrical mold, and immersing the mold in an aqueous solution of a molding material containing reinforcing fibers and an inorganic binder. , a step of applying a suction action within the mold to adhere the molding material to the outer peripheral surface of the mold to form a molded body material; a step of pressing the molded body material against the mold to adjust the shape of the molded body material; A process of opening both end openings of the mold and pulling the mold out of the molded body material, a process of heating and drying the molded body material, and a process of firing the molded body material and partially bonding the reinforcing fibers with an inorganic binder. Manufactured through.

(3) Problems to be Solved by the Invention However, as mentioned above, when the mold is pulled out from the molded material before the molded material is heated and dried, the molded material contains a large amount of water and has a tendency to retain its shape. Because of the poor properties, there is a problem that the molded body material is deformed and the dimensional accuracy of the fiber molded body is deteriorated.

An object of the present invention is to provide the manufacturing method capable of solving the above problems.

B. Structure of the Invention (1) Means for Solving Problems The present invention provides for sealing both end openings of a breathable cylindrical mold that collapses as a whole due to a pressing force applied to the outer peripheral surface of at least one end, and sealing the openings at both ends of the mold. The outer peripheral surface of the mold is masked, and then the mold is immersed in an aqueous solution of a molding material containing reinforcing fibers and an inorganic binder, and then suction is applied to the inside of the mold to remove the molding material from the mold. forming a molded body material by adhering it to the outer peripheral surface excluding masking; a step of pressing the molded body material against the mold to adjust the shape of the molded body material; a step of heating and drying the molded body material. a step of applying a pressing force to the outer peripheral surface of the one end of the mold to which adhesion of the molding material has been avoided by the masking to completely collapse the mold as a whole; firing the molded body material to remove the inorganic material; The method is characterized by using a step of partially binding the reinforcing fibers with a binder.

(2) Effect As mentioned above, since the molded body material is heated and dried while it is attached to the mold, there is no deformation of the molded body material due to pulling out the mold from the undried molded body material. It is possible to avoid such problems.

In addition, after the molded body material is heated and dried, a pressing force is applied to the outer peripheral surface of at least one end of the mold to completely collapse the mold, so the mold can be easily and reliably removed without deforming the molded body material. can be done.

(3) Example FIG. 1 shows a reinforcing cylindrical fiber molded body 1 obtained according to the present invention. It is partially bonded by silica sol, alumina sol, or a mixed sol thereof, and has countless voids into which the matrix can penetrate.

This fiber molded body 1 is used, for example, in order to obtain a fiber-reinforced composite cylinder sleeve by combining it with an aluminum alloy matrix when casting an aluminum alloy cylinder block.

Next, a method for manufacturing the fiber molded body 1 will be explained with reference to FIG.

As shown in Figure 2 a ₁ and a ₂ , shell sand (grain size
A cylindrical mold 2 with air permeability is formed using AFS35). This mold 2 has an outer diameter of 75 mm and a thickness of 5 mm. On the inner circumferential surface of the mold 2, a plurality of notch grooves (four in the illustrated example) having a V-shaped cross section extending over the entire length in the generatrix direction are formed at equal intervals on the circumference. The radial crushing strength of 2 is 45~
It is set to 50Kg/ ^cm2 . Therefore, if a pressing force exceeding the above-mentioned radial crushing strength is applied to the outer peripheral surface of at least one end of the mold 2, the bottom of each notch groove g will break and the entire mold 2 will collapse completely.

As shown in FIG. 2b, cap-shaped holders 3 ₁ and 3 ₂ are fitted onto the outer circumferential surface 2a of both ends of the mold 2, respectively, and the holders 3 ₁ and 3 ₂ are attached to the mold 2 by gluing, bolting, etc. and seal the openings at both ends.
As a result, the outer circumferential surfaces 2a of both ends of the mold 2 are covered by the circumferential walls 3a of the holders 3 ₁ and 3 ₂ , so that the outer circumferential surfaces 2a of both ends are respectively masked.

As shown in FIG. 2c, the mold 2 is immersed in an aqueous solution 4 of a molding material containing mixed fibers of carbon fibers and alumina fibers and alumina sol, and a vacuum pump 5
A suction action is applied inside the mold 2 to cause the molding material to adhere to the outer peripheral surface of the mold 2 to a predetermined thickness, thereby molding the molded body material 6. The molding operation using the vacuum pump 5 takes approximately 2 minutes. Since the outer circumferential surfaces 2a of both ends of the mold 2 are masked by both holders 3 ₁ and 3 ₂ , adhesion of the molding material to them is avoided.

As shown in FIG. 2d, the mold 2 is placed in the pressure container 7 of a rubber press, and pressurized air is supplied from the air pressure source 8 into the pressure container 7 to form the molded material 6 through the rubber 9. It is pressed against the outer circumferential surface of the mold 2 with a pressure of 8 to 10 kg/cm ² , thereby adjusting the shape of the molded body material 6 and determining the density at the same time.

As shown in FIG. 2e, both holders 3 ₁ and 3 ₂ are removed from the mold 2.

As shown in FIG. 2f, the mold 2 is placed in a drying oven 10.
The molded body material 6 is dried at 120° C. for 1 hour to evaporate and remove moisture. Molding mold 2
Since it is made of shell sand, it will not collapse at this drying temperature, and since its coefficient of thermal expansion is small, it will not cause any dimensional change to the molded body material 6.

FIG. 2 g ₁ and g ₂ show the disintegrator 11 of the mold 2.
The disintegrating machine 11 includes a machine stand 12, a pair of supports 13 erected opposite to the machine stand 12, a support shaft 14 installed between both supports 13, and a pair of support shafts 14 on the support shaft 14. A press lever 16 is rotatably attached to each end of the press section 15, and a pair of supports 17 are fixed oppositely to each other on the machine base 12 and support the mold 2.
, and a pair of press lever stoppers 18 which are similarly erected on the machine base 12 to face each other.

When collapsing mold 2,
is installed in the disintegrating machine 11 with its both end outer circumferential surfaces 2a placed on both support stands 17, respectively, and a pressing force exceeding the above-mentioned radial crushing strength is applied to both end outer circumferential surfaces 2a by the pressing lever 16. Since the bottom of each notch g is broken by this pressing force, the entire mold 2 completely collapses. In this case, since the mold 2 collapses into approximately four parts, it is easy to remove it, and since the molded body material 6 is dry, when the mold 2 is installed in the disintegrator 11. It does not deform during disintegration work, and is easy to handle.

As shown in FIG. 2h, the molded body material 6 is placed in a firing furnace 19, and the molded body material 6 is subjected to a firing treatment at 800° C. for one hour. As a result, the mixed fibers are partially bonded by the alumina sol, and the fiber molded body 1 shown in FIG. 1 is obtained.

Note that the collapse of the mold 2 is caused by the outer circumferential surface 2 of one end.
It is also possible to perform this by applying a pressing force only to a.

It is also possible to thermally collapse the mold 2 by heating it to a high temperature, but if such a method is adopted, cracks may occur in the molded body material 6 due to thermal expansion of the mold 2. Mechanical collapse means such as the present invention can completely avoid the problems associated with thermal collapse means.

C Effects of the Invention According to the present invention, since the molded body material is heated and dried while it is attached to the mold, the molded body material is deformed by pulling out the mold from the undried molded body material. You can avoid such problems.

In addition, after the molded material is heated and dried, a pressing force is applied to the outer peripheral surface of at least one end of the mold to completely collapse the entire mold, making it easy to remove the mold without deforming the molded material. It can be done reliably.

Therefore, according to the present invention, fiber molded articles with good dimensional accuracy can be efficiently produced.

[Brief explanation of drawings]

Fig. 1 is a perspective view of _the fiber molded body, and Fig. ₂ is an explanatory diagram of the manufacturing process of the fiber molded body. Figure g ₂ is the second figure g ₁
FIG. DESCRIPTION OF SYMBOLS 1... Fiber molded object, 2... Molding die, 3 ₁ , 3 ₂ ... Holder, 4... Aqueous solution of molding material, 5... Vacuum pump, 6
... Molded body material, 8... Air pressure source, 9... Rubber, 10...
Drying furnace, 11... Disintegrator, 19... Calcining furnace.

Claims (1)

[Scope of Claims] 1. The openings at both ends of a breathable cylindrical mold that collapses as a whole due to a pressing force applied to the outer peripheral surface of at least one end are sealed, and the outer peripheral surface of the one end is masked, and then the mold is immersed in an aqueous solution of a molding material containing reinforcing fibers and an inorganic binder, and then a suction action is applied inside the mold to cause the molding material to adhere to the outer circumferential surface of the mold, excluding the masking, to obtain a molded body material. a step of pressing the molded body material against the mold to adjust the shape of the molded body material; a step of heating and drying the molded body material; and a step of avoiding adhesion of the molding material by the masking. a step of completely collapsing the entire mold by applying a pressing force to the outer peripheral surface of the one end of the mold; a step of firing the molded body material and partially binding the reinforcing fibers with the inorganic binder. A method for producing a reinforcing cylindrical fiber molded article, characterized by using; and; 2. The method for manufacturing a reinforcing cylindrical fiber molded article according to claim 1, wherein a plurality of notch grooves extending over the entire length in the generatrix direction are formed on the inner circumferential surface of the mold.